Asiobaccha bicolor (Austen, 1893) comb. nov.

(Figures 4c, d, f, 14c)

Baccha bicolor Austen, 1893: 137 . Holotype: ♂, BMNH. Type locality: Indonesia: Misool Island. van der Wulp 1896: 121; Kertész 1910: 157; Edwards 1915: 409.

Baccha purpuricola of Walker 1864: 212 (in part).

Baccha sulica Austen, 1893: 144 (in part). Syn. nov. van der Wulp 1896: 121; Kertész 1910: 157.

Baccha semifumosa de Meijere, 1929: 384 . Syn. nov.

Baccha schistaceifrons de Meijere, 1929: 385 . Syn. nov.

Baccha (Allobaccha) bicolor of Knutson et al. 1975: 321.

Baccha (Allobaccha) sulica of Knutson et al. 1975: 323 (in part).

Allobaccha schistaceifrons of Thompson and Vockeroth 1989: 441; de Jong 2000: 191.

Allobaccha semifumosa of Thompson and Vockeroth 1989: 441; de Jong 2000: 193.

Episyrphus (Asiobaccha) bicolor of Thompson and Vockeroth 1989: 443.

Episyrphus (Asiobaccha) sulica of Thompson and Vockeroth 1989: 443 (in part).

Differential diagnosis

Species with a yellow face (Figure 4f), alula bare, narrower than costal cell, wing partly bare basally (Figure 14c), and without a mesonotal fringe. The abdominal pattern is identical to another two species with tergum 4 entirely black, A. loriae and A. tripartita, but differs by the wing microtrichia as stated in the key. Asiobaccha bicolor and A. tripartita differ from A. loriae by having the wing bare basally, easy to distinguish because both have always cell CuP and anal lobe partly bare basally (Figure 14c, d); sometimes A. loriae specimens may have very small bare areas in cell BM but cell CuP and anal lobe are always microtrichose (Figure 4c, d). On the other hand, A. tripartita has a more extensive microtrichia and the bare basal areas of the wing are on basal 1/3 – 1/2 cell BM only (Figure 14d).

Variation. Wing microtrichia is a bit variable in this species, as well as in the close A. tripartita . The bare area of cells BM and R vary between basal 1/2 to basal 3/4 or more for cell BM, and basal 1/3 to basal 1/2 for cell R. Furthermore, a few specimens have costal cell bare very basally. The specimen from New Ireland has the scutum entirely orange. Wing colouration varies from very dark to almost hyaline.

Length (N = 4). Body, 10.0 – 16.0 (13.5) mm; wing, 9.0 – 14.0 (12.1) mm.

Geographical distribution

Moluccas (Maluku and North Maluku Provinces, Indonesia), New Guinea Island, New Ireland Island, and Australia.

Genetics

The BOLD Process IDs for the DNA barcodes (5 ʹ – COI) for this species are: SYRAU037-15 (specimen CNC371757), SYROC420-15 (specimen CNC384959), SYROC450-15 (specimen CNC385002), and SYRAU038-15 (specimen CNC373577).

Type locality

Indonesia: West Papua Province, Raja Ampat Regency, Misool Island (Mysol), between 01°40 ‘ and 02°04 ’ S, and between 129°43 ʹ and 130°26 ʹ E .

Material examined

Type material. Holotype, male, deposited in The Natural History Museum, formerly British Museum (Natural History) (London, United Kingdom) and labelled: ‘ Holo- // type ’ [round, red margin] ‘ Type ’ [round, red margin] ‘ Baccha // bicolor // Aust. ’ [on the reverse of previous label, handwritten] ‘W. ’ [round, handwritten] ‘Mysol. // Wallace. ’ ‘ Baccha // bicolor // Aust. // Type. ’ [on the reverse of previous label, handwritten] ‘ HOLOTYPE // Asiobaccha // bicolor // (Austen) // det. X. Mengual 20 14’ [red] (specimen photographed).

Type material of Baccha sulica Austen, 1893 . Syntype, female, deposited in The Natural History Museum (London, UK) and labelled: ‘ SYN- // TYPE ’ [round, blue margin] ‘ Type ’ [round, red margin] ‘ Baccha // sulica // Aust . // Type’ [on the reverse of previous label, handwritten] ‘Sul’ [handwritten, round] ‘ Sula I . // Wallace’, ‘ Baccha // sulica // Aust . // Type’ [on the reverse of previous label, handwritten] ‘Sulica’ [handwritten].

Type material of Baccha schistaceifrons de Meijere, 1929 . Holotype, female, deposited in the Naturalis Biodiversity Center ( Leiden, The Netherlands) and labelled: ‘ Buru 1921 // Station 9 // leg. L.J.Toxopeus // 26.V’, ‘ Baccha // schistaceifrons // det. de Meijere . // Type’, ‘ Baccha // schistaceifrons // de Meijere, 1929 // ZMAN type DIPT.1045.1 ’ [red].

Type material of Baccha semifumosa de Meijere, 1929 . Lectotype, female, deposited in the Naturalis Biodiversity Center ( Leiden, The Netherlands) and labelled: ‘ Buru 1921 // Station 6 // leg. L.J.Toxopeus ’, ‘ Baccha // semifumosa // det. de Meijere . // Type’, ‘ Baccha // semifumosa // de Meijere, 1929 // ZMAN type DIPT.1048.1 ’ [red] ‘ LECTOTYPE // Baccha // semifumosa // de s. X. Mengual 20 14’ [red]. This specimen is here designated as lectotype to fix and ensure the universal and consistent interpretation of the name. Paralectotype, female, deposited in the Naturalis Biodiversity Center ( Leiden, The Netherlands) and labelled: ‘ Buru 1921 // Station 17 // leg. L.J.Toxopeus // 21/22.X’, ‘ Baccha // semifumosa // de Meijere, 1929 // ZMAN type DIPT.1048.2 ’ [red] ‘ PARALECTOTYPE // Baccha // semifumosa // de s. X. Mengual 20 14’ [yellow]. This specimen is here designated as paralectotype.

Nontype material. INDONESIA: North Maluku Prov., Taliabu Island, near Tubang, 40 m, Malaise trap 20, 9 – 20 March 1995, C.v. Achterberg, Y. Yasir [1♂, RMNH; 1♀, ZFMK, ZFMKDIP 00011906];..., Mangole Island, 2 km W Mandafuhl Camp, 70 m, Malaise trap 19, 7 – 24 March 1995, C.v. Achterberg, Y. Yasir [1♀, RMNH] ;..., Mangole Island, 450 m, 13 October – 2 November 1993, C.v. Achterberg [1♀, ZFMK, ZFMKDIP 00011903] ;..., West Obi, Obi Lake, 160 – 260 m, July – November 1953, A .M.R. Wegner [1♀, RMNH] ;..., Bacan Island ( Batjan), June – July 1953, A.M.R. Wegner [1♀, RMNH; 1♂, ZFMK, ZFMKDIP 00011905] ;..., Morotai Island, Bernstein [1♀, RMNH];..., Halmahera Island, Jailolo district, Kampung Pasir Putih, 0°53 ʹ N, 127°41 ʹ E, 1 – 14 February 1981, A.C. Messer and P.M. Taylor [1♂, USNM, USNMENT 00891192]; Maluku Prov., Ambon, October 1949, M.A. Lieftinck [1♂, RMNH]; Papua Prov., Star Range, Sibil, 1260 m, 04°54 ’ S, 140°40 ʹ E, 17 April 1959 [1♂, ZFMK, ZFMKDIP 00011908];..., Swart Valley, Karubaka, 1300 m, 03°35 ’ S, 138° 30 ʹ E, 7 November 1958, J.L. Gressit [1♀, BPBM];..., Lower Mist Camp, 1500 m, 03°30 ’ S, 139°05 ʹ E, 28 January 1939, L.J. Toxopeus [1♀, RMNH]. PAPUA NEW GUINEA: Central Prov., Bujacori (Bujkori), August 1890, L. Loria [1♀, MSNG];..., Owen Stanley Range, Goilala, Loloipa, 1 – 15 February 1958, W.W. Brandt [1♀, BPBM]; Morobe Prov., Huon Peninsula, Finschhafen, 80 m, 16 April 1963, J. Sedlacek [1♂, BPBM];..., Wau, 6 – 14 March 1974, H. Hippa, P.T. Lehtinen [1♀, MZH]; New Ireland Prov., Schleinitz Mts., Lelet Plateau, October 1959, W.W. Brandt [1♀, BPBM]. AUSTRALIA: Queensland, Mackay, 94 – 61, G. Turner [1♂, BMNH];..., Cry. Cascades, 29 December 1964, C.F. Ashby [1♀, USNM];..., McIlwraith Range, 30 km NE of Coen, Leo Creek Road, ca. 500 m, 29 June – 4 July 1976, G. B. and S.R. Monteith [1♂, USNM];..., 15 km NNW Cairns, 15 December 1991, M.E. Irwin, D.W. Webb, Malaise trap set across gravel stream bed [1♀, INHS];..., National Park, Cape Tribulation area, 15°07 ʹ 03.44 ʹʹ S, 145°04 ʹ 37.02 ʹʹ E, 5 December 2014, J.H., A.M. and A.W. Skevington [1♂, CNC, CNC 385019];..., Little Crystal Creek, near Paluma, 329 m, 8 December 1971, D.K. McAlpine, D.P. Sands, and G.A. Holloway [1♀, AMS, AMK 405063];..., Wooroonooran National Park, trail near Henrietta Creek Campground, 392 m, 17° 35 ʹ 57.02 ʹʹ S, 145°45 ʹ 11.02 ʹʹ E, 17 December 2014, J.H., A.M. and A.W. Skevington [1♀, CNC, CNC 384924];..., Summit of Mount Sorrow, 472 m, 16°04 ʹ 35.62 ʹʹ S, 145°26 ʹ 24.87 ʹʹ E, 14 December 2014, J.H. Skevington [4♂, CNC, CNC 371757, 371758, 371756, 384959];..., 6 December 2014,... [5♂, CNC, CNC 373577, 371558, 373803, 373804, 385002; 1♂, ZFMK, CNC 373805];..., Brisbane, Ashgrove, 6 May 1890, C. Wild [1♂, QM, QM _REG._NO._T 221488];..., Brisbane, 6 February 1890, C. Wild [1♂, QM, QM _REG._NO._T 221489];..., Cooloola, 17 – 28 August 1970, E.C. Dahms [1♀, QM, QM _REG._NO._T 221475];..., Mason Creek, Spencer Property, 20 m, 16°04 ʹ 60 ʹʹ S, 148°28 ʹ 00 ʹʹ E, 16 November 1998, C.J. Burwell [1♀, QM, QM _REG._NO._T 221490];..., National Park (Lamington), 19 March 1929 [1♀, QM, QM _REG._NO._T 221486];..., Peachester, 8 February 1973, E.C. Dahms [1♂, QM, QM _REG._NO._T 221487];..., West Claudie River, 5 December 1985, D. Yeates [1♀, QM, QM _REG._NO._T 220569];..., 4 December 1985,... [1♂, QM, QM _REG._NO._T 220568] .

Remarks

Baccha purpuricola Walker, 1859 was described by Walker (1858 /1859) from Aru Islands based on a single female. A few years later, Walker (1864, p. 212) described a male from Misool Island as the male of Baccha purpuricola . Later, Austen (1893) used this male from Misool as the holotype of his new species, Baccha bicolor . Austen (1893) explained that the yellow face of this specimen and different abdomen, actually more resembles Baccha moluccana Doleschall, 1857; but moluccana has a black scutellum and a medial black facial vitta. Since then, the confusion with purpuricola has been so frequent that there are specimens from A. bicolor, A. tripartita and A. loriae identified as Baccha purpuricola [= Allobaccha purpuricola (Walker, 1859)].

The type material of Baccha semifumosa and Baccha schistaceifrons was studied and both species were found to be the same species as bicolor (Austen) . Furthermore, one of the syntypes of Baccha sulica was found to also belong to A. bicolor .

This group of species ( A. bicolor, A. tripartita and A. loriae) is quite distinct, but the overall morphological similarity makes it difficult to identify each taxon (see Remarks under A. loriae). The author wanted to preserve the recognisable taxa that already had a name, but he is not sure if this is a single very variable species or a complex of many. Among the studied material, there is another manuscript name referring to a female given by P.H. van Doesburg, Baccha caeruleifrons . This female (Indonesia: Lower Mist Camp, 28 January 1939) is quite different from the other studied specimens: face and frons are white pollinose instead of yellow, white pilose instead of yellow; scutum and pleuron are darker, with not large yellow areas; and wing is less microtrichose, with cells BM and R entirely bare, cell CuP bare on basal 1/2, costal cell bare on basal 1/4 and subcostal cell bare on basal 3/5. The author preferred not to describe a new species based on a single specimen, as this specimen might represent an extreme of a variable species or a different one. Other sources of information (e.g. larval morphology, molecular markers) are needed to solve this morphological variability.

There is another manuscript name from P.H. van Doesburg, Baccha ambonensis (for one male from Ambon, October 1949), which has been never published; thus, it is not available, and refers to a specimen of A. bicolor .

Some specimens were identified as Episyrphus 88–17 Thompson, in litt.